Williams' time in office has "coincided with a period of turmoil, change and development in the Anglican Communion, and his careful leadership, deeply rooted in spirituality and theology, has strengthened and inspired us all in the Communion during this time," Kearon is quoted as saying.

The issues of homosexuality and women bishops have caused public tension and deep division within the Anglican Communion during Williams' tenure.

Although Williams came out against gay marriage, speaking of the dangers -- as he called them -- of "imposing" this on the rest of the population, he is generally perceived to be a liberal and is credited with pushing through the ordination of women bishops, expected later this year, which had been a major controversy.

The issue of gay rights has already riven the Anglican community in the United States and is anathema to most African Anglicans, the church's largest population.

General Synod member Andrea Minichiello Williams, who heads the British group Christian Concern, urged the Church of England to "move decisively" to find a successor who would provide a clear voice on divisive topics.

"There are many issues confronting our nation at the moment, which have raised the question of the place of Christian faith in British society. This is, therefore, a crucial time for the established church in this country to provide leadership, clarity and direction as many people want," she said in a statement.

Among those considered likely to take over from Williams is the Ugandan-born Archbishop of York, John Sentamu.

He sought refuge from Idi Amin in the United Kingdom in the 1970s but still holds conservative values more recognizable to the African bishops, drawing fire most recently for accusing gay rights' activists of imposing a "dictatorship" of their values.

The second-ranking figure in the Church of England, Sentamu is highly popular in the United Kingdom. He penned a column in the newly launched Sun on Sunday.

In a statement on his website, he said he had heard the news of Williams' resignation with "great sadness."

He paid tribute to Williams as "a remarkable and gifted leader who has strengthened the bonds of affection."

And, reflecting the controversy that has surrounded Williams, Sentamu added: "Despite his courageous, tireless and holy endeavour, he has been much maligned by people who should have known better."

Born in Wales in 1950, Williams studied theology at Cambridge and was an academic before going into the church. He became bishop of Monmouth in 1991 and was appointed the 104th archbishop of Canterbury in 2002.

Millions around the world watched him celebrate the marriage of Prince William and Catherine, Duchess of Cambridge, last April.